1. Field of the Invention
The present invention relates to a conductive film and a touch panel sensor provided with the same. Specifically, the present invention relates to a conductive film in which at least one of two electrode patterns constituted by combining a plurality of cells formed of a plurality of thin metal wires is a random pattern constituted by cells with irregularity, and a touch panel sensor provided with the same.
2. Description of the Related Art
Conventionally, a touch panel sensor of an electrostatic capacitive type or the like, which formed of a conductive film including a detection electrode having a two-layer structure having a strip-like electrode pattern constituted of a transparent conductive material such as indium tin oxide (ITO), or a mesh-like electrode pattern formed of a thin metal wire of silver, copper, or the like, is used in touch panel displays or the like (for example, refer to JP2013-69261A and JP2012-94115A).
JP2013-69261A discloses an electrode substrate for a touch panel having a conductor mesh formed by a predetermined non-periodic random mesh pattern not causing moire due to interference with periodic arrangement of pixels of a display panel, a touch panel using two layers of the electrode substrates through an insulating layer, and an image display device.
In the technique disclosed in JP2013-69261A, since the conductor mesh functions as a transparent conductive film, and transparency and conductivity required for a touch panel are secured. Further, in the mesh pattern of the conductor mesh, the average value N of the number of boundary line segments extending from one branch point is 3.0≤N<4.0, and the opening regions surrounded by the same number of boundary line segments do not have the same shape and have a predetermined non-periodic pattern. Thus, moire due to interference with periodic arrangement of pixels of the display panel does not occur.
On the other hand, JP2012-94115A discloses an electrostatic capacitive type touch panel in which a plurality of sensor electrodes of an upper electrode layer are formed into a mesh shape that is formed by a lattice of conductive thin wires, the direction of the thin wire of the lattice is inclined at an angle of 30° to 60° in the arranging direction of the sensor electrodes, the width of a non-conductive strip-like boundary region formed between adjacent sensor electrodes by disconnecting and removing the mesh-like conductive thin wires of the upper electrode randomly changes in a range of 10 μm to 100 μm in the extending direction of the sensor electrodes, and the average width value is 15 μm to 70 μm.
In the technique disclosed in JP2012-94115A, it is possible to provide a touch panel capable of preventing an interference fringe and obtaining an easily visible image, having excellent responsiveness in a large area, and making multi-touch possible.